JP2018536350A - Change of cyclic prefix (CP) length based on precoder mode selection - Google Patents

Abstract

  Each aspect allows to select a precoder mode for transmission, change a cyclic prefix (CP) length based on the selected precoder mode, and transmit a signal including the changed CP length To do. Changing the CP length may include searching for a value to change the nominal CP length using the selected precoder mode. After changing the CP length, information indicating the changed CP length may be transmitted to the receiver of the signal. Precoder mode selection may be based on feedback information indicating whether the receiver is requesting a CP length change. Precoder mode selection may be based on a received reference signal indicating the state of the communication channel. The reference signal may be used to select a precoder mode that results in minimum relative delay spread, maximum relative delay spread compression, maximum relative beamforming gain, and / or maximum relative throughput.

Description

Cross-reference to related applications This application is a provisional application 62 / 259,446 filed with the US Patent and Trademark Office on November 24, 2015, and a non-provisional application filed with the US Patent and Trademark Office on March 23, 2016 No. 15 / 078,087, all of which are hereby incorporated by reference for all applicable purposes, as if fully set forth below.

  Aspects of the present disclosure generally relate to wireless communication systems, and more particularly, to changing cyclic prefix (CP) length based on precoder mode selection.

  Wireless communication networks are widely deployed to provide various communication services such as telephone, video, data, messaging, broadcast, and so on. Such networks, usually multiple access networks, support communication for multiple users by sharing available network resources. Within such a wireless network, various data services may be provided including voice, video, and email. The spectrum allocated to such a wireless communication network can include allowed and / or unlicensed spectrum. The licensed spectrum is generally limited in its use for wireless communications except for authorized usage as regulated by government agencies or other agencies within a given area. Unlicensed spectrum is generally free to use within limits without the purchase or use of such permission. As the demand for mobile broadband access continues to increase, research and development continues to evolve wireless communication technologies to meet the growing demand for mobile broadband access and improve the overall user experience. Yes.

  The following presents a simplified summary of such aspects in order to enable a basic understanding of one or more aspects of the present disclosure. This summary is not an extensive overview of all contemplated features of this disclosure, but it does identify the major or important elements of all aspects of this disclosure and is intended to cover the scope of any or all aspects of this disclosure. It is not something that is defined. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

  In one aspect, the present disclosure provides an apparatus for wireless communication. The apparatus includes a transceiver, a memory, and at least one processor communicatively coupled to the transceiver and the memory. At least one processor may be configured to select a precoder mode for transmission. The at least one processor may be further configured to change the cyclic prefix (CP) length based on the selected precoder mode. The at least one processor may be further configured to transmit a signal including the changed CP length utilizing the transceiver.

  In another aspect, the present disclosure provides a method for wireless communication. The method may include selecting a precoder mode for transmission. The method may also include changing the CP length based on the selected precoder mode. The method may also include transmitting a signal that includes the changed CP length.

  In yet another aspect, the present disclosure provides a computer-readable medium that stores computer-executable code. The computer executable code may include instructions configured to select a precoder mode for transmission. These instructions may be further configured to change the CP length based on the selected precoder mode. These instructions may be further configured to transmit a signal that includes the changed CP length.

  In a further aspect of the present disclosure, the present disclosure provides an apparatus for wireless communication. The apparatus may include means for selecting a precoder mode for transmission. The apparatus may also include means for changing the CP length based on the selected precoder mode. The apparatus may also include means for transmitting a signal that includes the changed CP length.

  These and other aspects of the disclosure will be more fully understood upon review of the following detailed description. Other aspects, features, and embodiments of the disclosure will become apparent to those skilled in the art upon review of the following description of specific exemplary embodiments of the disclosure in conjunction with the accompanying drawings. The features of the present disclosure may be described with respect to several embodiments and figures that follow, but all embodiments of the present disclosure include one or more of the advantageous features described herein. Can do. In other words, although one or more embodiments may be described as having some advantageous features, one or more of such features may also be described in the present disclosure as described herein. May be used according to various embodiments. Similarly, although example embodiments may be described below as device embodiments, system embodiments, or method embodiments, such example embodiments may be implemented in various devices, systems, and methods. Please understand that you can.

FIG. 4 illustrates an example of various communications between a scheduling entity and one or more subordinate entities, in accordance with aspects of the present disclosure. FIG. 4 illustrates an example hardware implementation of a scheduling entity in accordance with aspects of the present disclosure. FIG. 6 illustrates an example of a hardware implementation of a dependent entity according to aspects of the present disclosure. FIG. 4 illustrates an example scheduling entity that communicates with subordinate entities in an access network according to aspects of the disclosure. FIG. 3 is a diagram illustrating an example of multipath communication according to an aspect of the present disclosure. It is a figure showing an example of a time line corresponding to multipath communication by the mode of this indication. FIG. 6 is a diagram illustrating an example of a time for a signal to arrive at a dependent entity in accordance with aspects of the present disclosure. FIG. 6 is a diagram illustrating a further example of a time at which a signal arrives at a dependent entity according to aspects of the disclosure. FIG. 4 illustrates an example of maximum delay spread for various signals transmitted by a scheduling entity, in accordance with aspects of the present disclosure. FIG. 6 illustrates aspects relating to changing the number of paths used in precoder mode, according to aspects of the disclosure. FIG. 6 is a diagram illustrating an example of a relationship between signal quality and throughput according to aspects of the present disclosure. FIG. 6 illustrates an example implementation in accordance with aspects of the present disclosure. FIG. 4 illustrates various methods and / or processes performed by a scheduling entity in accordance with aspects of the present disclosure.

  The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of enabling a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, some structures and components are shown in block diagram form in order to avoid obscuring such concepts.

  The concepts presented throughout this disclosure may be implemented across a wide variety of telecommunication systems, network architectures, and communication standards. For example, the 3rd Generation Partnership Project (3GPP) is a standards body that defines several wireless communication standards for networks with evolved packet systems (EPS), sometimes referred to as Long Term Evolution (LTE) networks. . In LTE networks, each packet may utilize the same or similar latency target. Thus, the LTE network may provide general purpose latency settings. Evolution versions of LTE networks such as 5th generation (5G) networks involve many different types of services and / or applications (e.g. web browsing, video streaming, VoIP, mission critical applications, multi-hop networks, real-time feedback) Remote operation, remote surgery, etc.) may be provided. The concepts presented throughout this disclosure are, in addition or alternatively, published by a wide variety of wireless local area networks (WLANs) and corresponding communication standards (e.g., the Institute of Electrical and Electronics Engineers (IEEE), such as IEEE 802.11). Standard)).

  FIG. 1 shows a diagram 100 illustrating an example of various communications between a scheduling entity 102 and one or more dependent entities 104 in accordance with aspects of the present disclosure. In general, scheduling entity 102 is a node or device responsible for scheduling traffic in a wireless communication network, including various downlink (DL) transmissions and uplink (UL) transmissions. Scheduling entity 102 may be referred to as a scheduler and / or any other suitable terminology without departing from the scope of this disclosure. Scheduling entity 102 includes base station, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set, extended service set, access point, node B, user equipment (UE), mesh node, relay, peer, and It may be / or any other suitable device or may be present therein.

  In general, the dependent entity 104 includes scheduling information and / or control information, including but not limited to scheduling grants, synchronization or timing information, or other control information from another entity in the wireless communication network, such as the scheduling entity 102. Node or device that receives Dependent entity 104 may be referred to as a schedule and / or any other suitable term without departing from the scope of this disclosure. Dependent entity 104 is a UE, mobile phone, smartphone, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, Access terminal, mobile terminal, wireless terminal, remote terminal, handset, terminal, user agent, mobile client, client, mesh node, peer, session initiation protocol telephone, laptop, notebook, netbook, smart book, personal digital assistant, Satellite radio, global positioning system device, multimedia device, video device, digital audio player, camera, game console, entertainment device, vehicle structure May be, or within, an element, a wearable computing device (e.g., smart watch, glasses, health or fitness tracker, etc.), appliance, sensor, vending machine, and / or any other suitable device May be present.

  A “control channel” as used herein may be used to convey grant information. Scheduling entity 102 may transmit DL data channel 106 and DL control channel 108. Dependent entity 104 may transmit UL data channel 110 and UL control channel 112. The channels shown in FIG. 1 are not necessarily all of the channels that may be utilized by scheduling entity 102 and / or subordinate entity 104. One skilled in the art will recognize that other channels such as other data, control, and feedback channels may be utilized in addition to the illustrated channels. As used herein, the term “downlink” or “DL” may refer to a point-to-multipoint transmission originating from the scheduling entity 102 and is used herein as “uplink” or “UL”. The term may refer to a point-to-point transmission originating from subordinate entity 104. According to aspects of the present disclosure, the terms “communicate” and / or “communicating” refer to transmission and / or reception. Those skilled in the art will appreciate that such communication may be performed by many types of techniques without departing from the scope of this disclosure. As used herein, the term `` DL-centric time division duplex (TDD) subframe '' means that a portion of information may be communicated in the UL direction, but a substantial portion of information (e.g., large (Part) refers to the TDD subframe communicated in the DL direction. Also, as used herein, the term `` UL-centric time division duplex (TDD) subframe '' means that a portion of information may be communicated in the DL direction, but a substantial portion of information (e.g., , Most) refers to TDD subframes that are communicated in the UL direction.

  FIG. 2 is a drawing 200 illustrating an example of a hardware implementation of the scheduling entity 102 in accordance with various aspects of the present disclosure. The scheduling entity 102 may include a user interface 212. User interface 212 may be configured to receive one or more inputs from a user of scheduling entity 102. In some configurations, the user interface 212 may be a keypad, display, speaker, microphone, joystick, and / or any other suitable component of the scheduling entity 102. User interface 212 may exchange data via bus interface 208. Scheduling entity 102 may include a transceiver 210. The transceiver 210 may be configured to communicate with another device to receive and / or transmit data. The transceiver 210 provides a means for communicating with another device via a wired transmission medium and / or a wireless transmission medium. The transceiver 210 may be configured to perform such communications using various types of techniques without departing from the scope of the present disclosure.

  The scheduling entity 102 may also include a memory 214, one or more processors 204, a computer readable medium 206, and a bus interface 208. Bus interface 208 may provide an interface between bus 216 and transceiver 210. Memory 214, one or more processors 204, computer readable medium 206, and bus interface 208 may be connected to one another via bus 216. The processor 204 may be communicatively coupled to the transceiver 210 and / or the memory 214.

  The processor 204 may include a precoder circuit 220. Precoder circuit 220 may include hardware components that provide a means for selecting a precoder mode for transmission, and / or may execute various algorithms that provide such means. The processor 204 may also include a cyclic prefix (CP) circuit 221. The CP circuit 221 may include hardware components that provide a means for changing the CP length based on the selected precoder mode, and / or execute various algorithms that provide such means. May be. The processor 204 may also include a communication circuit 222. The communication circuit 222 may include hardware components that provide a means for transmitting a signal that includes a modified CP length, and / or may execute various algorithms that provide such means. .

  In some configurations, the CP circuit 221 may include hardware components that provide a means for retrieving a value for changing the nominal CP length using the selected precoder mode, and / or Alternatively, various algorithms that provide such means may be executed. In some configurations, the communication circuit 222 may include a hardware component that provides a means for transmitting information indicative of the changed CP length to a receiver of the signal after changing the CP length, and Various algorithms that provide such means may be implemented. In some configurations, the communication circuit 222 may include a hardware component that provides a means for transmitting information indicative of the selected precoder mode to a receiver of the signal after selecting the precoder mode. And / or various algorithms providing such means may be implemented.

  The means for selecting a precoder mode may be configured according to any one or more of the various aspects described in more detail herein. In some configurations, the means for selecting a precoder mode receives feedback information from the signal receiver indicating whether the signal receiver is requesting a change in CP length and based on the feedback information It may be configured to select a mode. In some configurations, the means for selecting the precoder mode is adapted to receive a reference signal indicative of the state of the communication channel and to select a precoder mode that provides a minimum relative delay spread based on the received reference signal. It may be configured. In some configurations, the means for selecting a precoder mode receives a reference signal indicative of the state of the communication channel and selects a precoder mode that provides maximum relative delay spread compression based on the received reference signal. May be configured. In some configurations, the means for selecting the precoder mode receives a reference signal indicative of the state of the communication channel and selects a precoder mode that provides a maximum relative beamforming gain based on the received reference signal. May be configured. In some configurations, the means for selecting a precoder mode is configured to receive a reference signal indicative of a state of the communication channel and select a precoder mode that provides maximum relative throughput based on the received reference signal. May be.

  The above description illustrates a non-limiting example of the processor 204 of the scheduling entity 102. While various circuits 220, 221 and 222 have been described above, those skilled in the art will recognize that the processor 204 may include various other circuits 223 that are additions and / or alternatives to the circuits 220, 221 and 222 described above. It will be understood that it is good. Such other circuitry 223 may provide a means for performing any one or more of the functions, methods, processes, features, and / or aspects described herein.

  The computer readable medium 206 may include a variety of computer executable instructions. Computer-executable instructions may include computer-executable code configured to perform various functions described herein and / or to enable various aspects described herein. Computer-executable instructions may be executed by various hardware components of scheduling entity 102 (eg, any of processor 204 and / or its circuits 220, 221, 222, 223). Computer-executable instructions may be part of various software programs and / or software modules.

  Computer readable medium 206 may include precoder instructions 240. Precoder instructions 240 may include computer-executable instructions configured to select a precoder mode for transmission. The computer readable medium 206 may also include CP instructions 241. CP instructions 241 may include computer-executable instructions configured to change the CP length based on the selected precoder mode. The computer readable medium 206 may also include communication instructions 242. Communication instructions 242 may include computer-executable instructions configured to send a signal that includes the changed CP length.

  In some configurations, the CP instruction 241 may also include a computer-executable instruction configured to retrieve a value for changing the nominal CP length using the selected precoder mode. In some configurations, the communication instructions 242 may also include computer-executable instructions configured to send information indicating the changed CP length to the receiver of the signal after changing the CP length. In some configurations, the communication instructions 242 may also include computer-executable instructions configured to send information indicating the selected precoder mode to the receiver of the signal after selecting the precoder mode. .

  Precoder instructions 240 may include computer-executable instructions configured according to any one or more of the various aspects described in more detail herein. In some configurations, a precoder instruction 240 configured to select a precoder mode receives feedback information from the signal receiver indicating whether the signal receiver is requesting a CP length change, and the feedback information May be configured to select a precoder mode based on In some configurations, the precoder instruction 240 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that results in a minimum relative delay spread based on the received reference signal. In some configurations, the precoder instruction 240 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides maximum relative delay spread compression based on the received reference signal. . In some configurations, the precoder instruction 240 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides maximum relative beamforming gain based on the received reference signal. . In some configurations, the precoder instruction 240 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides maximum relative throughput based on the received reference signal.

  The above description illustrates a non-limiting example of the computer readable medium 206 of the scheduling entity 102. While various computer-executable instructions 240, 241, 242 have been described above, those skilled in the art will appreciate that the computer-readable medium 206 is an addition and / or alternative to the computer-executable instructions 240, 241, 242 described above. It will be appreciated that other computer-executable instructions 243 may also be included. Such other computer-executable instructions 243 may be configured for any one or more of the functions, methods, processes, features, and / or aspects described herein.

  The memory 214 may include various memory modules. The memory module may be configured to store various values and / or information and have the values and / or information read by the processor 204 or any of its circuits 220, 221, 222, 223. The memory module stores various values and / or information, and the values and / or information when executing any of the computer-executable code included in the computer-readable medium 206, or its instructions 240, 241, 242, 243. May be configured to be read. The memory 214 may include precoder information 230. Precoder information 230 includes information of various types, quantities, settings, configurations, and / or formats related to a precoder or precoder mode according to one or more of the various aspects described in more detail herein. May be included. The memory 214 may also include CP information 231. The CP information 231 may include various types, amounts, settings, configurations, and / or types of information related to the CP as described in more detail herein. While various types of data in the memory 214 have been described above, those skilled in the art will appreciate that the memory 214 may include various other data that are additions and / or alternatives to the information 230, 231 described above. It will be understood. Such other data may be associated with any one or more of the functions, methods, processes, features, and / or aspects described herein.

  Those skilled in the art will appreciate that the scheduling entity 102 may include alternative and / or additional features without departing from the scope of this disclosure. In accordance with various aspects of the present disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system that includes one or more processors 204. Examples of one or more processors 204 include a microprocessor, microcontroller, digital signal processor (DSP), field programmable gate array (FPGA), programmable logic device (PLD), state machine, gate logic, discrete hardware circuitry , And other suitable hardware configured to perform the various functions described throughout this disclosure. The processing system may be implemented with a bus architecture schematically represented by bus 216 and bus interface 208. Bus 216 may include any number of interconnecting buses and bridges depending on the particular application of the processing system and the overall design constraints. Bus 216 may link various circuits including one or more processors 204, memory 214, and computer readable medium 206 together. Bus 216 may link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits.

  One or more processors 204 may be responsible for general processing, including management of bus 216 and execution of software stored on computer readable medium 206. The software, when executed by one or more processors 204, causes the processing system to perform various functions described below for any one or more devices. The computer-readable medium 206 may also be used to store data that is manipulated by one or more processors 204 when executing software. Software, whether called by software, firmware, middleware, microcode, hardware description language, or other name, instructions, instruction set, code, code segment, program code, program, subprogram, It shall be interpreted broadly to mean software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and the like. The software may reside on computer readable media 206.

  The computer readable medium 206 may be a non-transitory computer readable medium. Non-transitory computer readable media include, by way of example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact disks (CDs) or digital versatile disks (DVDs)), Smart cards, flash memory devices (for example, cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software and / or instructions that may be accessed and read by a computer. The computer-readable medium 206 may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and / or instructions that may be accessed and read by a computer. The computer-readable medium 206 may reside within the processing system, may be external to the processing system, or may be distributed across multiple entities that include the processing system. The computer readable medium 206 may be embodied within a computer program product. By way of example, and not limitation, a computer program product may include a computer-readable medium in packaging material. Those skilled in the art will recognize how to best perform the above-described functions presented throughout this disclosure, depending on the particular application and the overall design constraints imposed on the overall system.

  FIG. 3 is a drawing 300 illustrating an example of a hardware implementation of the dependent entity 104 in accordance with various aspects of the present disclosure. The dependent entity 104 may include a user interface 312. User interface 312 may be configured to receive one or more inputs from a user of subordinate entity 104. In some configurations, user interface 312 may be a keypad, display, speaker, microphone, joystick, and / or any other suitable component of subordinate entity 104. User interface 312 may exchange data via bus interface 308. Dependent entity 104 may include a transceiver 310. The transceiver 310 may be configured to communicate with another device to receive data and / or transmit data. The transceiver 310 provides a means for communicating with another device via a wired transmission medium and / or a wireless transmission medium. The transceiver 310 may be configured to perform such communications using various types of techniques without departing from the scope of the present disclosure.

  The dependent entity 104 may include a memory 314, one or more processors 304, a computer readable medium 306, and a bus interface 308. Bus interface 308 may provide an interface between bus 316 and transceiver 310. Memory 314, one or more processors 304, computer readable media 306, and bus interface 308 may be connected to one another via bus 316. The processor 304 may be communicatively coupled to the transceiver 310 and / or the memory 314.

  The dependent entity 104 may include a memory 314, one or more processors 304, a computer readable medium 306, and a bus interface 308. Bus interface 308 may provide an interface between bus 316 and transceiver 310. Memory 314, one or more processors 304, computer readable media 306, and bus interface 308 may be connected to one another via bus 316. The processor 304 may be communicatively coupled to the transceiver 310 and / or the memory 314.

  The processor 304 may include a precoder circuit 320. Precoder circuit 320 may include hardware components that provide a means for selecting a precoder mode for transmission, and / or may execute various algorithms that provide such means. The processor 304 may also include a CP circuit 321. The CP circuit 321 may include hardware components that provide a means for changing the CP length based on the selected precoder mode and / or execute various algorithms that provide such means. May be. The processor 304 may also include a communication circuit 322. The communication circuit 322 may include hardware components that provide a means for transmitting a signal that includes a modified CP length, and / or may execute various algorithms that provide such means. .

  In some configurations, the CP circuit 321 may include a hardware component that provides a means for retrieving a value for changing the nominal CP length using a selected precoder mode, and Various algorithms that provide such means may be implemented. In some configurations, the communication circuit 322 may include hardware components that provide a means for transmitting information indicating the changed CP length to a receiver of the signal after changing the CP length, and Various algorithms that provide such means may be implemented. In some configurations, the communication circuit 322 may include a hardware component that provides a means for transmitting information indicative of the selected precoder mode to a receiver of the signal after selecting the precoder mode. And / or various algorithms providing such means may be implemented.

  The means for selecting a precoder mode may be configured according to any one or more of the various aspects described in more detail herein. In some configurations, the means for selecting a precoder mode receives feedback information from the signal receiver indicating whether the signal receiver is requesting a change in CP length and based on the feedback information It may be configured to select a mode. In some configurations, the means for selecting the precoder mode is adapted to receive a reference signal indicative of the state of the communication channel and to select a precoder mode that provides a minimum relative delay spread based on the received reference signal. It may be configured. In some configurations, the means for selecting a precoder mode receives a reference signal indicative of the state of the communication channel and selects a precoder mode that provides maximum relative delay spread compression based on the received reference signal. May be configured. In some configurations, the means for selecting the precoder mode receives a reference signal indicative of the state of the communication channel and selects a precoder mode that provides a maximum relative beamforming gain based on the received reference signal. May be configured. In some configurations, the means for selecting a precoder mode is configured to receive a reference signal indicative of a state of the communication channel and select a precoder mode that provides maximum relative throughput based on the received reference signal. May be.

  The above description illustrates a non-limiting example of the processor 304 of the dependent entity 104. While various circuits 320, 321, and 322 have been described above, those skilled in the art will appreciate that the processor 304 may include various other circuits 323 that are additions and / or alternatives to the circuits 320, 321, and 322 described above. It will be understood that it is good. Such other circuitry 323 may provide a means for performing any one or more of the functions, methods, processes, features, and / or aspects described herein.

  Computer readable medium 306 may include precoder instructions 340. Precoder instructions 340 may include computer-executable instructions configured to select a precoder mode for transmission. Computer readable medium 306 may also include CP instructions 341. CP instructions 341 may include computer-executable instructions configured to change the CP length based on the selected precoder mode. The computer readable medium 306 may also include communication instructions 342. Communication instructions 342 may include computer-executable instructions configured to send a signal that includes the changed CP length.

  In some configurations, the CP instructions 341 may also include computer-executable instructions configured to retrieve a value for changing the nominal CP length using the selected precoder mode. In some configurations, the communication instructions 342 may also include computer-executable instructions configured to send information indicating the changed CP length to the receiver of the signal after changing the CP length. In some configurations, the communication instructions 342 may also include computer-executable instructions configured to send information indicating the selected precoder mode to a receiver of the signal after selecting the precoder mode. .

  Precoder instructions 340 may include computer-executable instructions configured according to any one or more of the various aspects described in more detail herein. In some configurations, a precoder instruction 340 configured to select a precoder mode receives feedback information from the receiver of the signal indicating whether the receiver of the signal requests a change in CP length, and the feedback information May be configured to select a precoder mode based on In some configurations, the precoder instruction 340 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that results in a minimum relative delay spread based on the received reference signal. In some configurations, the precoder instruction 340 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides maximum relative delay spread compression based on the received reference signal. . In some configurations, the precoder instruction 340 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides a maximum relative beamforming gain based on the received reference signal. . In some configurations, the precoder instruction 340 may be configured to receive a reference signal indicative of the state of the communication channel and select a precoder mode that provides maximum relative throughput based on the received reference signal.

  The above description illustrates a non-limiting example of a computer readable medium 306 of a dependent entity 104. While various computer-executable instructions 340, 341, 342 have been described above, those skilled in the art will appreciate that various computer-readable media 306 are additions and / or alternatives to the computer-executable instructions 340, 341, 342 described above. It will be appreciated that other computer-executable instructions 343 may also be included. Such other computer-executable instructions 343 may be configured for any one or more of the functions, methods, processes, features, and / or aspects described herein.

  The memory 314 may include various memory modules. The memory module may be configured to store various values and / or information and have the values and / or information read by the processor 304 or any of its circuits 320, 321, 322, 323. The memory module stores various values and / or information, and those values and / or information when executing any of the computer-executable code included in the computer-readable medium 306 or its instructions 340, 341, 342, 343. May be configured to be read. Memory 314 may include precoder information 330. Precoder information 330 includes various types, quantities, settings, configurations, and / or forms of information related to a precoder or precoder mode according to one or more of the various aspects described in more detail herein. May be included. The memory 314 may also include CP information 331. The CP information 331 may include various types, quantities, settings, configurations, and / or types of information related to the CP as described in more detail herein. While various types of data in the memory 314 have been described above, those skilled in the art will appreciate that the memory 314 may include various other data that are additions and / or alternatives to the information 330, 331 described above. It will be understood. Such other data may be associated with any one or more of the functions, methods, processes, features, and / or aspects described herein.

  Those skilled in the art will appreciate that dependent entities 104 may include alternative and / or additional features without departing from the scope of the present disclosure. In accordance with various aspects of the present disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system that includes one or more processors 304. Examples of one or more processors 304 include a microprocessor, microcontroller, DSP, FPGA, PLD, state machine, gate logic, discrete hardware circuitry, and various functions described throughout this disclosure. Other suitable hardware configured is included. The processing system may be implemented with a bus architecture schematically represented by bus 316 and bus interface 308. Bus 316 may include any number of interconnecting buses and bridges depending on the particular application of the processing system and the overall design constraints. Bus 316 may link various circuits including one or more processors 304, memory 314, and computer-readable medium 306 together. Bus 316 may link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits.

  One or more processors 304 may be responsible for general processing, including management of bus 316 and execution of software stored on computer readable medium 306. The software, when executed by one or more processors 304, causes the processing system to perform various functions described below for any one or more devices. The computer-readable medium 306 may also be used for storing data that is manipulated by one or more processors 304 when executing software. Software, whether called by software, firmware, middleware, microcode, hardware description language, or other name, instructions, instruction set, code, code segment, program code, program, subprogram, It shall be interpreted broadly to mean software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and the like. The software may reside on computer readable media 306.

  The computer readable medium 306 may be a non-transitory computer readable medium. Non-transitory computer readable media include, by way of example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., CD or DVD), smart cards, flash memory devices (e.g., cards Stick, or key drive), RAM, ROM, PROM, EPROM, EEPROM, registers, removable disks, and any other suitable for storing software and / or instructions that may be accessed and read by a computer Media included. The computer-readable medium 306 may also include, by way of example, carrier waves, transmission lines, and any other suitable medium for transmitting software and / or instructions that may be accessed and read by a computer. The computer readable medium 306 may reside within the processing system, may be external to the processing system, or may be distributed across multiple entities that include the processing system. The computer readable medium 306 may be embodied within a computer program product. By way of example, and not limitation, a computer program product may include a computer-readable medium in packaging material. Those skilled in the art will recognize how to best perform the above-described functions presented throughout this disclosure, depending on the particular application and the overall design constraints imposed on the overall system.

  FIG. 4 shows a diagram 400 illustrating a scheduling entity 102 communicating with subordinate entities 104 in an access network according to aspects of this disclosure. In DL, the upper layer packet from the core network is supplied to the controller / processor 475. The controller / processor 475 implements the L2 layer function. In DL, the controller / processor 475 enables header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio to dependent entities 104 based on various priority metrics. Allocate resources. Controller / processor 475 is also responsible for HARQ operations, retransmission of lost packets, and signaling to subordinate entity 104.

  A transmit (TX) processor 416 implements various signal processing functions for the L1 layer (ie, physical layer). Signal processing functions include coding and interleaving to facilitate forward error correction (FEC) at the dependent entity 104 and various modulation schemes (e.g., two phase shift keying (BPSK), four phase shift keying (QPSK), M Mapping to signal constellations based on phase shift keying (M-PSK), M quadrature amplitude modulation (M-QAM)) is included. The coded and modulated symbols are then divided into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT). A physical channel carrying the time-domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. The channel estimates from channel estimator 474 are used to determine coding and modulation schemes and may be used for spatial processing. The channel estimate may be derived from a reference signal and / or channel state feedback transmitted by the dependent entity 104. Each spatial stream may then be fed to a different antenna 420 via a separate transmitter 418TX. Each transmitter 418TX may modulate an RF carrier with a respective spatial stream for transmission.

  Each receiver 418RX may be configured to receive wireless signals of various types, schemes, configurations, and / or modulations. RX processor 470 may be configured to receive, decode, demodulate, and / or otherwise process any UL signal received by receiver 418RX. In some examples, UL signals are adapted to a multi-user version of a modulation scheme called orthogonal frequency division multiple access (OFDMA), or orthogonal frequency division multiplexing (OFDM). In some examples, the UL signal is adapted for single carrier frequency division multiple access (SC-FDMA). Such signals may coexist in some examples. In other words, RX processor 470 and receiver 418RX may perform UL communication using waveforms that may co-exist in OFDMA and SC-FDMA.

  In the dependent entity 104, each receiver 454RX receives a signal via its respective antenna 452. Each receiver 454RX recovers the information modulated on the RF carrier and provides the information to a receive (RX) processor 456. The RX processor 456 performs various signal processing functions of the L1 layer. RX processor 456 may perform spatial processing on the information to recover any spatial stream destined for subordinate entity 104. If multiple spatial streams are destined for the dependent entity 104, those spatial streams may be combined by the RX processor 456 as a single OFDM symbol stream. RX processor 456 then transforms the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point transmitted by the scheduling entity 102. These soft decisions may be based on channel estimates calculated by channel estimator 458. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by the scheduling entity 102 on the physical channel. The data and control signals are then provided to the controller / processor 459.

  The controller / processor 459 implements the L2 layer. The controller / processor can be associated with a memory 460 that stores program codes and data. Memory 460 may be referred to as a computer readable medium. In UL, the controller / processor 459 performs demultiplexing, packet reassembly, decoding, header decompression, and control signal processing between the transport and logical channels to recover higher layer packets from the core network. Do. The upper layer packet is then provided to the data sink 462, which represents all protocol layers above the L2 layer. Various control signals may be provided to the data sink 462 for L3 processing. The controller / processor 459 is also responsible for error detection using an acknowledgment (ACK) and / or negative acknowledgment (NACK) protocol to support HARQ operations.

  In UL, data source 467 is used to provide upper layer packets to controller / processor 459. Data source 467 represents all protocol layers above the L2 layer. The controller / processor 459 is responsible for logical channels and transports based on header compression, encryption, packet segmentation and reordering, and radio resource allocation by the scheduling entity 102, as well as the functions described for DL transmission by the scheduling entity 102. Implement L2 layer for user plane and control plane by multiplexing with channels. Controller / processor 459 is also responsible for HARQ operations, retransmission of lost packets, and signaling to scheduling entity 102.

  The channel estimate derived by the channel estimator 458 from the reference signal or feedback transmitted by the scheduling entity 102 is used by the TX processor 468 to select an appropriate coding and modulation scheme and facilitate spatial processing. May be. Spatial streams generated by TX processor 468 may be provided to different antennas 452 via separate transmitters 454TX. Each transmitter 454TX may modulate an RF carrier with a respective spatial stream for transmission.

  Each transmitter 454TX may be configured to transmit wireless signals of various types, schemes, configurations, and / or modulations. TX processor 468 may be configured to generate, encode, modulate, and / or otherwise generate any UL signal transmitted by transmitter 454TX. In some examples, the UL signal may be adapted to OFDMA. In some examples, the UL signal may be adapted for SC-FDMA. Such signals may coexist in some examples. In other words, TX processor 468 and transmitter 454TX may perform UL communication using waveforms that co-exist in OFDMA and SC-FDMA.

  The UL transmission is processed at the scheduling entity 102 in a manner similar to that described for the receiver function at the subordinate entity 104. Each receiver 418RX receives a signal through its respective antenna 420. Each receiver 418RX recovers the information modulated on the RF carrier and supplies the information to the RX processor 470. The RX processor 470 may implement the L1 layer.

  The controller / processor 475 implements the L2 layer. The controller / processor 475 can be associated with a memory 476 that stores program codes and data. Memory 476 may be referred to as a computer readable medium. In UL, the controller / processor 475 allows demultiplexing, packet reassembly, decoding, header decompression, control signal processing between transport and logical channels to recover higher layer packets from subordinate entities 104. I do. Upper layer packets from the controller / processor 475 may be supplied to the core network. The controller / processor 475 is also responsible for error detection using the ACK and / or NACK protocol to support HARQ operations.

FIG. 5 is a diagram 500 illustrating an example of multipath communication in accordance with aspects of the present disclosure. This example shows how a signal can take multiple paths as it propagates from a scheduling entity 102 to a dependent entity 104. For example, path _A represents a direct path from scheduling entity 102 to subordinate entity 104. The transmitted signal may also travel from the scheduling entity 102 to the dependent entity 104 via an indirect path. Some paths may be reflected from various obstacles 502, 504 before reaching the subordinate entity 104. As an example, the path _B represents a path where the signal is reflected from the obstacle 502 that changes the transmission destination of the signal to the subordinate entity 104. As another example, path _C represents a path where the signal reflects from another obstacle 504 that redirects the signal to the subordinate entity 104. In the example shown in FIG. 5, the path _C is longer than the path _B. Thus, a signal propagating in path _B arrives at the dependent entity 104 before a signal propagating in path _{C. A} signal propagating in path _A arrives before both signals propagating in path _B and path _C.

FIG. 6 is a diagram 600 illustrating an example of a timeline corresponding to multipath communication according to an aspect of the present disclosure. FIG. 6 shows that the signal propagating in path _A arrives earlier than the signal propagating in path _B. FIG. 6 also shows that the signal propagating in path _B arrives earlier than the signal propagating in path _C. The signal shown in FIG. 6 indicates that each symbol may have a CP. In general, CP refers to the repeated portion of a symbol that precedes the symbol. In other words, a CP is positioned in front of a symbol, and the CP repeats a part of the symbol (for example, an end portion). For example, as shown in FIG. 6, CP ₁ repeats the end portion of symbol ₁ . Usually, the CP is discarded by the receiver (eg, the dependent entity 104), but the CP has various purposes. One of the many purposes of CP is to function as a guard interval to mitigate intersymbol interference. For example, CP ₂ may mitigate interference between symbol ₁ and symbol ₂ .

  The CP may have various lengths without departing from the scope of the present disclosure. In some existing systems, the CP length may utilize 5% to 10% of the physical channel resources. For those skilled in the art, any reference to “length” herein refers to related concepts such as duration, time, duration, bits, and other suitable concepts without departing from the scope of this disclosure. It will be understood that there are also. Thus, any reference herein to “CP length” refers to CP overhead, CP duration, CP time, CP duration, CP bits, and other suitable CP related aspects without departing from the scope of this disclosure. In some cases.

In general, when precoding is not performed, the length suitable for CP increases as the number of paths taken by the signal increases. One reason for this general relationship is that the energy from an echo (e.g., a signal propagating in path _B and path _C ) of a particular symbol (e.g., symbol ₁ ) is transferred to another symbol (e.g., symbol ₂ ) Is that it takes more time to dissipate before receiving. Otherwise, the echo from the preceding symbol (eg, symbol ₁ ) may interfere with the current symbol (eg, symbol ₂ ). Thus, in some situations, a relatively large CP length may be appropriate as the number of paths increases.

However, an unnecessarily long CP length can adversely affect system performance (eg, reduce throughput). As described above, the CP is typically discarded at the receiver (eg, dependent entity 104). Nevertheless, the CP utilizes communication resources that may be utilized to convey information that would otherwise not be discarded at the receiver (eg, dependent entity 104). Thus, although CP is utilized in many implementations of wireless communications, the appropriate length for CP may differ under various circumstances.

FIG. 7 is a diagram 700, 750 illustrating examples of times at which a signal arrives at the subordinate entity 104. Those skilled in the art will appreciate that the example presented in FIG. 7 shows a general general time relationship and is not scaled to show exact time increments. First diagram 700 shows an example of the time when signals from path _A , path _B , and path _C arrive at subordinate entity 104 when scheduling entity 102 does not perform enhanced precoding for transmission.

  In general, precoding may be utilized for wireless communication by multi-antenna devices. Precoding may involve multiple data streams emitted from transmit antennas with independent appropriate weights to maximize link throughput at a receiver (eg, dependent entity 104). In other words, precoding takes advantage of transmit diversity by weighting the information stream, possibly using information or knowledge about the wireless communication channel. Precoding may support beamforming. In general, beamforming refers to a spatial filtering technique used for directional signal transmission. In other words, the transmitter (e.g., scheduling entity 102) applies various weights to the various antennas of the transmitter (e.g., scheduling entity 102) to minimize multipath, thereby echoing at the receiver (subordinate entity 104). Is kept to a minimum, and thus the CP length appropriate for its transmission may be shortened. Because wireless communication devices may have multiple antennas that can be utilized for wireless communication, enhanced precoding techniques substantially reduce multipath and thus minimize the CP length required for a particular transmission. There is a case to suppress to. In some configurations, precoding and / or beamforming may be applied on a per tone basis. In other words, per tone beamforming / precoding may further compress the delay spread in some cases (eg, in large scale multiple input multiple output (MIMO) communication systems). For example, the CP length may be about 50% shorter or in some cases much shorter.

The first diagram 700 shows an example of the time that a signal arrives at the subordinate entity 104 when the extended precoding technique is not utilized by the scheduling entity 102, while the second diagram 750 shows the enhanced precoding technique by the scheduling entity 102. An example of the time when a signal arrives at the subordinate entity 104 when is used is shown. Comparing the two diagrams 700, 750, it can be seen that the enhanced precoding technique may reduce the amount of time a signal echo is received at the dependent entity 104. For example, signals in path _B and path _C arrive at a time close to time T ₁ instead of arriving at a time close to times T ₂ and T ₃ when the extended precoding technique is utilized by scheduling entity 102 To do. In other words, when precoding is applied to the transmission signal, many of the echoes of the multipath echo collapse and basically become a single energy peak.

  FIG. 8 shows diagrams 800, 850 illustrating further examples of times at which signals arrive at the dependent entity 104. FIG. First diagram 800 shows an example of a time for a signal to arrive at dependent entity 104 when the extended precoding technique is not utilized by scheduling entity 102. In contrast, a second diagram 850 shows an example of the time at which a signal arrives at the dependent entity 104 when the extended precoding technique is utilized by the scheduling entity 102. Comparing the two diagrams 800, 850, it can be seen that the enhanced precoding technique may reduce the duration in which signal echoes are received at the dependent entity 104. For example, when extended precoding techniques are utilized by the scheduling entity 102, the energy from the echo of the transmitted signal, if detected, is not detected in the period t + 50 to t + 150, but t Detected in periods prior to +50.

In some aspects, the diagrams 800, 850 may be referred to as power delay profiles (PDPs), each of which may include a plot of the power of the channel impulse response. A channel (eg, a wideband channel) may have several (eg, L) (non-zero) multipath components, which may be referred to as “taps” or “chips”. For example, in the first diagram 800 of FIG. 8, nine multipath components (eg, taps or chips) are shown, with each multipath component having a different amplitude. These multipath components correspond to different paths through which the signal traveled or propagated from N _T transmit antennas (e.g. at scheduling entity 102) to N _R receive antennas (e.g. at subordinate entity 104) May be.

From a mathematical point of view, each of these multi-path components (e.g., tap or chip) _{h l1, h l2,..} ., Sometimes referred to as h _lL, in this case, h _i is, i-th multipath Refers to a vector with _NT complex numbers corresponding to multipath components (e.g. taps or chips) from each transmit antenna to each receive antenna array in the component (e.g. taps or chips), and multipath components (e.g. taps) (Or chip) position index is

May be represented. The frequency domain representation of the channel may be expressed as:

In some embodiments, H _K represents a vector with N _T complex corresponding to the channel estimation value of the k-th subcarrier of each transmission received (TX-RX) antenna pair.

A subset of may be called C. That is, C may refer to a subset of related multipath component indices. In some situations, the choice of C can affect precoder design. For example, C may be selected such that one or more performance metrics are optimized or maximized. This disclosure describes many non-limiting examples of performance metrics such as relative delay spread, relative delay spread compression, relative beamforming gain, relative throughput, and many other performance metrics.

  The frequency domain representation of the channel may be expressed as follows using C:

The above equation, is sometimes referred to as a "sparse" representation of H _K. According to some aspects of the present disclosure, a transmitter (eg, scheduling entity 102) may design a precoder for each subcarrier k according to the following equation:

In the above equation, P refers to the total power (which may be normalized to satisfy some transmit power constraint conditions), and * refers to the conjugate transpose operation of

After applying such a precoder, the channel for each subcarrier may be expressed as G _k = H _k P _k . In some aspects, G _k may represent an effective channel that a receiver (eg, dependent entity 104) may observe after a transmitter (eg, scheduling entity 102) applies a precoder on each subcarrier. In the time domain, such a channel may be expressed as:

In the above equation, N refers to the discrete Fourier transform (DFT) size, and “mod” refers to the modulo operation. The PDP after applying such a precoder may be defined by | g _l | ² and this formula may be referred to as the effective channel after precoding.

FIG. 9 shows diagrams 900 950 illustrating examples of maximum delay spread for various signals transmitted by the scheduling entity 102. As used herein, “delay spread” is a measure for multipath of a communication channel. Delay spread is between the arrival time of the earliest significant multipath signal (for example, a signal propagating in path _A ) and the arrival time of the latest significant multipath signal (for example, a signal propagating in path _C ). May be interpreted as a difference between Delay spread may be used in characterizing wireless communication channels.

  As used herein, the reduction of delay spread may be referred to as “delay spread compression” without departing from the scope of this disclosure. Such delay spread reduction (e.g., delay spread compression) is due to the fact that when precoding is applied to the transmitted signal, many of the echoes of the multipath echo collapse and basically become a single energy peak. May be realized.

  As used herein, “maximum delay spread” is the number of durations or time samples required to reduce the received symbol energy by some amount (eg, 20 decibels (dB)) from the average power of the symbol. Point to. In other words, maximum delay spread refers to a measure of how long it takes for the power (after the symbol is finished) to be lower by some amount (eg, -20 dB) than the average energy of the symbol. There is a case.

  First diagram 900 shows examples of various maximum delay spreads when extended precoding techniques are not utilized by scheduling entity 102. In contrast, a second diagram 950 shows examples of various maximum delay spreads when enhanced precoding techniques are utilized by the scheduling entity 102. Comparing the two diagrams 900, 950, it can be seen that enhanced precoding techniques may reduce maximum delay spread. For example, n TX antennas may have a maximum delay spread of 10x + 500 nanoseconds (x represents any positive value) when the extended precoding technique is not utilized by the scheduling entity 102, and n The TX antennas may have a maximum delay spread of x + 4 nanoseconds when extended precoding techniques are utilized by the scheduling entity 102.

  FIG. 10 shows diagrams 1000, 1050 illustrating aspects related to changing the number of paths used in the precoder mode. In general, the number of paths used in the precoder mode refers to the number of paths that the precoder mode takes into account when weighting the various signals transmitted by its antenna. The first diagram 1000 shows how the number of paths used in the precoder mode may affect the root mean square (RMS) delay spread. In general, RMS delay spread corresponds to the standard deviation of the delay of the signal echo (eg, reflection). For example, RMS delay spread may indicate variability in arrival times of signal echoes (eg, reflections). The receiver may match the receiver signal / symbol reception to the average delay spread of the multipath transmission. However, the receiver may take into account delay spread variability (eg, deviation). In other words, the same average delay spread may have different RMS delay spread values depending on the delay variability of the signal echo (eg, reflection). Thus, in some situations, RMS delay spread may be a factor used in CP length selection. For example, the receiver may select a CP length that accepts a particular percentage or rate of delay in the signal echo (eg, reflection). In the first diagram 1000 shown in FIG. 10, RMS delay spread is measured in nanoseconds.

  The first diagram 1000 shows in part that the RMS delay spread decreases as the number of paths used in the precoder mode increases. For example, as the number of paths used in precoder mode increases from 1p to 6p (p represents any positive integer), RMS delay spread decreases from about a + 360 to about a + 40 (a is Represents any positive value). However, in another part, the first diagram 1000 shows that the RMS delay spread may remain relatively constant or may increase in some cases as the number of paths used in precoder mode increases. It shows that there is. For example, when the number of paths used in precoder mode increases from 6p to 9p, the RMS delay spread remains relatively constant (about a + 40) and then increases (about a + 40 to about a + Up to 80).

  In FIG. 10, a second diagram 1050 shows how the number of paths used in the precoder mode may affect the beamforming gain. In this example, the beamforming gain is measured in decibels. In general, beamforming gain refers to the energy gain or power gain that is achieved as a result of precoding the transmitted signal prior to wireless transmission. First, the diagram 1050 shows that the main path energy increases substantially as the number of paths included in the precoder mode increases. Second, the diagram 1050 shows that the multipath energy remains relatively constant even when the number of paths used in the precoder mode changes.

  FIG. 11 shows a diagram 1100 illustrating an example of the relationship between signal quality and throughput when a precoder mode is used that may result in a significant reduction in delay spread. This relationship is shown for various CP lengths for channels that typically require 7p CP length to reach the peak throughput of the system. In this example, the throughput is measured in megabits per second (Mbps) and the CP length is measured in microseconds. `` Signal quality '' shown in FIG. 11 and described herein may refer to a carrier to interference noise ratio (CINR), signal to noise ratio (SNR), and / or various other suitable measures of signal quality. is there. First, this FIG. 1100 shows that the throughput may decrease as the CP length decreases when the signal quality is relatively high. When the signal quality is relatively high (eg, 3q to 5q), the throughput is substantially reduced (eg, reduced from 6z to 4.5z) when the CP length is reduced from 5p to 2p. In this case, each of p and z represents an arbitrary positive value. Second, this FIG. 1100 shows that the throughput does not necessarily decrease as the CP length decreases, and that in some scenarios the peak throughput increases. This can happen because a shorter CP length may still be sufficient to deal with compressed delay spread. As can be seen by comparing the peak throughput for the CP lengths of 5p and 7p in FIG. 1100 of FIG. 11, a relatively high peak throughput may be achieved. The reason is that the CP length is relatively short, which may allow a relatively large amount of data information to be transmitted. For those skilled in the art, when the signal quality is relatively high (eg 3q-5q), the throughput is substantially reduced even if the CP length is reduced from 2p to p or the CP length is reduced from 7p to 5p. It will be noted that this may not be due to the compressed delay spread caused by using a particular precoder mode.

  FIG. 12 shows a diagram 1200 illustrating an example implementation in accordance with aspects of the present disclosure. Block 1206 conceptually represents precoder mode selection. In general, precoder mode selection refers to selection of a precoder mode for various types of wireless communications. As used herein, “precoder mode” refers to precoder type, precoder configuration, precoder scheme, precoder settings, precoder parameters, precoder weights, and / or precoder modes without departing from the scope of this disclosure. May refer to and / or include any other suitable embodiment. In some configurations, the precoder mode may correspond to a specific transmission mode (TM). For example, the device may estimate the precoder mode based on TM. Precoder mode selection may be based on many types of information without departing from the scope of this disclosure.

  A non-limiting example of such information (based on precoder mode selection criteria) is a received reference signal, represented by block 1202. For example, the dependent entity 104 may send a reference signal (eg, a sounding signal) to the scheduling entity 102. The reference signal may include various types of information such as the state of a wireless communication channel (eg, without precoding). The scheduling entity 102 may select an appropriate precoder mode based on the received reference signal. The particular precoder mode selected by the scheduling entity may differ between various configurations. In some configurations, the scheduling entity 102 may select a precoder mode that results in minimum relative delay spread. In some configurations, the scheduling entity 102 may select a precoder mode that results in maximum relative delay spread compression. The aspects relating to delay spread and delay spread compression have been described in more detail with reference to FIGS. 9 and 10, and therefore, these aspects will not be repeated. In some configurations, the scheduling entity 102 may select a precoder mode that yields the maximum relative beamforming gain. Aspects relating to beamforming gain are described in more detail with reference to FIG. 10, and therefore these aspects will not be repeated. In some configurations, the scheduling entity 102 may select a precoder mode that results in maximum relative throughput. Aspects relating to throughput are described in more detail with reference to FIG. 11, and therefore, these aspects will not be repeated.

  Another non-limiting example of such information (based on precoder mode selection) is received feedback information, represented by block 1204. For example, the scheduling entity 102 may send a signal to the dependent entity 104, and the dependent entity 104 may report feedback information back to the scheduling entity 102. The feedback information may relate to CP length, delay spread, throughput, and / or various other suitable aspects without departing from the scope of this disclosure. In some examples, the feedback information may indicate whether dependent entity 104 is requesting a CP length change. The feedback information may also take a variety of forms and / or configurations without departing from the scope of the present disclosure. In some examples, the feedback information may be in the form of a single bit (eg, a happy bit), which may indicate whether dependent entity 104 is requesting a CP length change. . In some examples, the feedback information may also include additional bits. If the dependent entity 104 is requesting a CP length change, this additional bit may indicate whether the change is to increase or decrease the CP length. The scheduling entity 102 may select a specific precoder mode based on such feedback information.

  Block 1208 conceptually represents the selected precoder mode. Block 1210 conceptually represents a change in CP length. According to various aspects of the present disclosure, the CP length change is based on the selected precoder mode. In many existing systems, the CP length is not based on the selected precoder mode. In some existing systems (eg, some telecommunications systems), the CP length may be fixed or predetermined. In some other existing systems (eg, some wireless local access networks), the CP length may be changed based on information about the wireless communication channel rather than the selected precoder mode. In other words, existing systems may change the CP length in the same way even when the selected precoder mode changes. In other words, in an existing system, selecting a specific precoder mode does not necessarily affect how the CP length is changed. However, changing the CP length based on precoder mode selection has many advantages over existing systems. For example, the selected precoder mode may be able to estimate the delay spread (or delay spread compression) of the wireless transmission, so the transmitter may recognize the appropriate CP length for that particular wireless transmission. A suitable CP length is sufficient to minimize intersymbol interference (e.g., as described in more detail above with reference to FIG. 6), but (e.g., FIG. 6 and FIG. The CP length may be not long enough to adversely affect throughput (as described in more detail above with reference to 11). Thus, enabling the scheduling entity 102 to change the CP length based on precoder mode selection may improve the efficiency of wireless communication.

  The mechanisms and / or techniques for the scheduling entity 102 to implement CP length changes based on the selected precoder mode may vary based on specific design constraints of the particular wireless communication device, network, and / or technology There is. Although some examples of such mechanisms and / or techniques may be described herein, one of ordinary skill in the art will appreciate that various other alternatives are within the scope of this disclosure. In some examples, the scheduling entity 102 may change the CP length by searching for a value to change the nominal CP length using the selected precoder mode. For example, a lookup table may store such values. This value can be a fixed quantity (e.g. any real number), a multiplier (e.g. 2x), a fraction (e.g. 1/2), and / or a nominal CP length (e.g. default CP length, predetermined CP length, pre- It may be any other suitable parameter that can change the set CP length, previous CP length, etc.). Such values may be updated as appropriate based on various system parameters, network conditions, and other suitable triggers. Each of these values may be mapped to a specific precoder mode. Based on the selected precoder mode, the corresponding CP length may be retrieved and used to change the CP length.

  A signal may be transmitted after the CP length is changed. Block 1212 conceptually represents signal transmission. The transmitted signal may be precoded using the selected precoder mode, as described above with reference to blocks 1206, 1208. The transmitted signal may also include a modified CP length, as described above with reference to block 1210.

  FIG. 13 shows a drawing 1300 that illustrates various methods and / or processes performed by the scheduling entity. Those skilled in the art will appreciate that such methods and / or processes may be performed by a variety of other suitable devices without departing from the scope of the present disclosure. At block 1302, the scheduling entity 102 may select a precoder mode for transmission. In some examples, the scheduling entity 102 may select a precoder mode based on feedback information received from the subordinate entity 104. The feedback information may indicate whether the dependent entity 104 is requesting a CP length change. In some examples, the scheduling entity 102 may select a precoder mode based on the reference signal received from the subordinate entity 104. The scheduling entity 102 may select a precoder mode that results in minimum relative delay spread, maximum relative delay spread compression, maximum beamforming gain, and / or maximum relative throughput based on the reference signal.

  At block 1304, the scheduling entity 102 may change the CP length based on the selected precoder mode. In some examples, the scheduling entity 102 may change the CP length by searching for a value to change the nominal CP length using the selected precoder mode. Various other techniques and / or mechanisms for changing the CP length based on the selected precoder mode are within the scope of this disclosure. At block 1306, the scheduling entity 102 may send a signal including the changed CP length. In some examples, the signal may be precoded using the selected precoder mode. Further explanation regarding precoding and CP length is presented herein with reference to eg FIG. 6 and will therefore not be repeated. In some configurations, at block 1308, the scheduling entity 102 may send specific information to the receiver of the signal (eg, the dependent entity 104). In some examples, such information may indicate the changed CP length. In some examples, such information may indicate the selected precoder mode. A receiver (eg, dependent entity 104) may be prepared to receive a precoded signal that includes the modified CP length by providing any of these types of information. For example, the receiver has information regarding a portion corresponding to the CP length in the received signal.

  The methods and / or processes described with reference to FIG. 13 are presented for purposes of illustration and are not intended to limit the scope of the present disclosure. The method and / or process described with reference to FIG. 13 may be performed in a different sequence than the method and / or process shown in FIG. 13 without departing from the scope of the present disclosure. Further, some or all of the methods and / or processes described with reference to FIG. 13 may be performed individually and / or collectively without departing from the scope of the present disclosure. It should be understood that the specific order or hierarchy of steps in the methods disclosed represents an exemplary process. It is understood that a particular order or hierarchy of steps in the method may be rearranged based on design preferences. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically stated.

102 Scheduling entity
104 Dependent entities
102 _A scheduling entity # 1
102 _B Scheduling entity # 2
104 _A Dependent Entity # 1
104 _B Dependent Entity # 2
106 DL data channel
108 DL control channel
110 UL data channel
112 UL control channel
204 processor
206 Computer-readable media
208 bus interface
210 transceiver
212 User interface
214 memory
216 bus
220 Precoder circuit
221 CP circuit
222 Communication circuit
223 circuit
230 Precoder information
231 CP information
240 precoder instructions
241 CP instruction
242 Communication command
243 Computer-executable instructions
304 processor
306 Computer-readable medium
308 Bus interface
310 transceiver
312 User interface
314 memory
316 bus
320 Precoder circuit
321 CP circuit
322 Reference signal circuit
323 circuit
330 Precoder information
331 CP information
340 Precoder instruction
341 CP instruction
342 Communication command
343 Computer-executable instructions
416 Transmit (TX) processor
418TX transmitter
418RX receiver
420 Antenna
452 Antenna
454TX transmitter
454RX receiver
456 RX processor
458 channel estimator
459 Controller / Processor
460 memory
462 Data Sync
467 Data Source
468 TX processor
470 RX processor
474 channel estimator
475 Controller / Processor
476 memory
500 Figure
502, 504 Obstacle
600 Figure
700 Figure 1
750 Figure 2
800 Figure 1
850 Figure 2
900 Figure 1
950 Figure 2
1000 Figure 1
1050 Figure 2
1100 fig
1200 Figure
1300 fig

Claims (30)

A wireless communication method,
Selecting a precoder mode for transmission;
Changing a cyclic prefix (CP) length based on the selected precoder mode;
Transmitting a signal including the changed CP length. The step of changing the CP length based on the selected precoder mode comprises:
The method of claim 1, comprising searching for a value to change a nominal CP length using the selected precoder mode.   2. The method according to claim 1, further comprising transmitting information indicating the changed CP length to a receiver of the signal after changing the CP length.   2. The method of claim 1, further comprising: after selecting the precoder mode, transmitting information indicating the selected precoder mode to a receiver of the signal. The step of selecting the precoder mode comprises:
Receiving feedback information from a receiver of the signal, the feedback information indicating whether the receiver is requesting a change in the CP length; and
2. The method of claim 1, comprising: selecting the precoder mode based on the feedback information. The step of selecting the precoder mode comprises:
Receiving a reference signal indicating the state of the communication channel;
Selecting a precoder mode that results in a minimum relative delay spread based on the received reference signal. The step of selecting the precoder mode comprises:
Receiving a reference signal indicating the state of the communication channel;
Selecting a precoder mode that results in maximum relative delay spread compression based on the received reference signal. The step of selecting the precoder mode comprises:
Receiving a reference signal indicating the state of the communication channel;
Selecting a precoder mode that results in a maximum relative beamforming gain based on the received reference signal. The step of selecting the precoder mode comprises:
Receiving a reference signal indicating the state of the communication channel;
Selecting a precoder mode that results in a maximum relative throughput based on the received reference signal.   The method of claim 1, wherein the signal is precoded using the selected precoder mode. A device configured for wireless communication,
A transceiver,
Memory,
At least one processor communicatively coupled to the transceiver and the memory, the at least one processor comprising:
Select the precoder mode for transmission,
Change the cyclic prefix (CP) length based on the selected precoder mode,
An apparatus configured to transmit a signal including the changed CP length. The change of the CP length based on the selected precoder mode is
12. The apparatus of claim 11, comprising retrieving a value for changing a nominal CP length using the selected precoder mode. The at least one processor is
12. The apparatus of claim 11, further configured to send information indicating the changed CP length to a receiver of the signal after the change of the CP length. The at least one processor is
12. The apparatus of claim 11, further configured to send information indicating the selected precoder mode to a receiver of the signal after the selection of the precoder mode. The selection of the precoder mode is
Receiving feedback information from a receiver of the signal, wherein the feedback information indicates whether the receiver is requesting a change in the CP length; and
12. The apparatus of claim 11, comprising selecting the precoder mode based on the feedback information. The selection of the precoder mode is
Receiving a reference signal indicating the state of the communication channel;
12. The apparatus of claim 11, comprising selecting a precoder mode that provides minimum relative delay spread based on the received reference signal. The selection of the precoder mode is
Receiving a reference signal indicating the state of the communication channel;
12. The apparatus of claim 11, comprising selecting a precoder mode that provides maximum relative delay spread compression based on the received reference signal. The selection of the precoder mode is
Receiving a reference signal indicating the state of the communication channel;
12. The apparatus of claim 11, comprising: selecting a precoder mode that provides a maximum relative beamforming gain based on the received reference signal. The selection of the precoder mode is
Receiving a reference signal indicating the state of the communication channel;
12. The apparatus of claim 11, comprising selecting a precoder mode that provides maximum relative throughput based on the received reference signal.   12. The apparatus of claim 11, wherein the signal is precoded using the selected precoder mode. A device for wireless communication,
Means for selecting a precoder mode for transmission;
Means for changing a cyclic prefix (CP) length based on the selected precoder mode;
Means for transmitting a signal comprising said changed CP length. The means for changing the CP length based on the selected precoder mode is:
23. The apparatus of claim 21, configured to retrieve a value for changing a nominal CP length using the selected precoder mode.   23. The apparatus of claim 21, further comprising means for transmitting information indicating the changed CP length to a receiver of the signal after changing the CP length.   23. The apparatus of claim 21, further comprising means for transmitting information indicative of the selected precoder mode to a receiver of the signal after selecting the precoder mode.   23. The apparatus of claim 21, wherein the signal is precoded using the selected precoder mode. A computer readable storage medium storing computer executable code including instructions, wherein the instructions are:
Select the precoder mode for transmission,
Change the cyclic prefix (CP) length based on the selected precoder mode,
A computer readable storage medium configured to transmit a signal including the changed CP length. The change of the CP length based on the selected precoder mode is
27. The computer readable storage medium of claim 26, comprising retrieving a value for changing a nominal CP length using the selected precoder mode. The instructions are
27. The computer readable storage medium of claim 26, further configured to transmit information indicating the changed CP length to a receiver of the signal after changing the CP length. The instructions are
27. The computer readable storage medium of claim 26, further configured to transmit information indicative of the selected precoder mode to a receiver of the signal after selecting the precoder mode.   27. The computer readable storage medium of claim 26, wherein the signal is precoded using the selected precoder mode.